Scientists Discover Underwater City Built By Octopuses

Octopus city found off coast of Australia

Octopuses have generally been viewed as lonely creatures. They are smart, quick and have a remarkable ability to solve problems but they mostly do all this alone and don’t interact much with other octopuses.

Now, researchers have discovered an underwater ‘octopus city’ off the coast of Australia and it harbors up to 15 individual octopuses. In the site, octopuses have been observed interacting and communicating with each other, suggesting that these deep sea creatures might not be strictly solitary.

“These behaviors are the product of natural selection, and may be remarkably similar to vertebrate complex social behavior. This suggests that when the right conditions occur, evolution may produce very similar outcomes in diverse groups of organisms.” Lead researcher David Scheel of Alaska Pacific University told Quartz.

The new site is the second octopus settlement found in the Jervis Bay area of Australia and researchers have named it Octlantis. The octopuses found in the settlement belong to a species known as Octopus tetricus or gloomy octopuses, characterized by white eye pupil and orange-rust arms.

The first settlement, named Octopolis, was discovered in 2009, where more than16 gloomy octopuses were found involved in social contact besides mating. The site is composed of several dens as well as a human-made flat object around 30 centimeters long.

The newly-discovered settlement is just few hundred miles away from the first one and also contains several dens and features similar to the first settlement. The discovery supports the idea that octopuses can socialize under certain conditions.

“At both sites there were features that we think may have made the congregation possible – namely several seafloor rock outcroppings dotting an otherwise flat and featureless area," said co-researcher Stephanie Chancellor from University of Illinois at Chicago. "In addition to the rock outcroppings, octopuses who had been inhabiting the area had built up piles of shells left over from creatures they ate, most notably clams and scallops. These shell piles, or middens, were further sculpted to create dens, making these octopuses true environmental engineers."

Researchers came to that conclusion after diving to the place and recording several hours of footage with GoPro cameras. In the footage, researchers witnessed mating, chasing, signs of aggression and other signaling behavior in octopuses. While little is known about the solitary lives of octopuses, a few octopus settlements with multiple individuals interacting socially have been found in recent years.

"Animals were often pretty close to each other, often within arm's reach. Some of the octopuses were seen evicting other animals from their dens. There were some apparent threat displays where an animal would stretch itself out lengthwise in an 'upright' posture and its mantle would darken. Often another animal observing this behavior would quickly swim away…but we still don't really know much about octopus behavior.” said Chancellor. “More research will be needed to determine what these actions might mean.”